Assessing expandable Global Positioning System collars for moose neonates

Tyler R. Obermoller, Glenn D. Delgiudice, William J. Severud

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


Deploying Global Positioning System (GPS) collars on ungulate neonates would offer notable advantages to examining their life history and influence on population performance. During 2013 and 2014, we deployed expandable GPS collars on 74 moose (Alces alces) neonates in Minnesota, USA, to estimate survival and cause-specific mortality during their first year. Collars slipped from 10.5% and 62.5% of calves at 15.8 (±4.5 [SE]) and 27.9 (±8.1) days postcapture in 2013 and 2014, respectively, from premature deterioration of the breakaway mechanism or excessive band expansion. We conducted various controlled tests on the bands to quantify potential design flaws. We placed 8 bands (with GPS package) around a polyvinyl chloride (PVC) pipe outdoors (exposed to weather) with clear plastic tubing (sleeve) to prevent neck abrasions, 7 collars outdoors with no sleeve, and 7 collars indoors with no sleeve. We dropped each pipe 10 cm 50 times in the morning and in the afternoon daily for 4 weeks to simulate animal movement and test elastic memory. Circumference of bands from the 3 treatment groups increased 14.6 (±2.5), 8.5 (±2.9), and 3.9 (±2.4) cm, respectively, with 41.9% attributed to the sleeve, 26.9% to simulated animal movement, and 31.2% to weather exposure. Circumference of control group bands (indoors, not bounced) did not change. After design modifications were made to the collar, the band length increased only 1.5 ± 0.6 cm during a 4-week trial. Subsequently, we placed 6 of these collars on confined and sheltered Holstein dairy calves; 5 retained their collar during an 8-week test. After increasing the strength of the expandable loops via sewing, we placed 4 collars on pastured Angus beef calves. Three of 4 slipped their collars at 42.4 (±8.9) days. Our results indicate additional modifications of the band are needed before GPS-collaring of moose neonates is resumed.

Original languageEnglish (US)
Pages (from-to)314-320
Number of pages7
JournalWildlife Society Bulletin
Issue number2
StatePublished - Jun 2018

Bibliographical note

Funding Information:
We appreciate the assistance of K. Foshay, T. Enright, B. Betterly, L. Ross, and M. Haas for help with collar testing and M. Carstensen, E. Hildebrand, D. Pauly, M. Dexter, E. Butler, M. Schrage, R. Moen, A. McGraw, M. Keech, and R. Wright for support during the 2013–2014 capture seasons. We thank R. Schulte and Vectronic Aerospace GmbH, for their consistent efforts in attempting to improve the Global Positioning System collar and concern for the well-being of the moose neonates. We also would like to thank S. Anderson and C. Mattson for allowing us to collar their neonatal Holstein dairy and Angus beef calves. We would also like to acknowledge A. Rodgers, B. Patterson, R. Moen, D. Mech, and S. Barber-Meyer for assistance in collar design consultations. Finally, we thank the Associate Editor, and 2 anonymous reviewers for their suggestions to improve the manuscript. This study was funded in part by the Minnesota Environmental and Natural Resources Trust Fund, the Wildlife Restoration (Pittman–Robertson) Program, and MNDNR Section of Wildlife’s Wildlife Populations and Research Unit.

Publisher Copyright:
© The Wildlife Society, 2018


  • Alces alces
  • calves
  • expandable GPS collars
  • moose
  • neonates


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